BMI in Children

Updated:Jan 3,2014

BMI is an important tool to identify childhood obesity.

Are you worried that you child could be overweight? Nearly 1 in 3 kids or teens in the U.S. are overweight or obese, nearly three times the number in 1963. Carrying extra weight as a child or teenager can pose significant health risks, both during childhood and into adulthood.

Maintaining a healthy weight during childhood is especially important for heart health. Research shows that nearly 60 percent of overweight children age 5 to 17 had at least one risk factor for cardiovascular disease and 25 percent had two or more. And obese kids have an 80 percent chance of staying obese their entire lives.

Psychological stress, including low self-esteem, caused by social stigma of being obese

What is BMI? Body Mass Index is calculated using weight and height measurements and is an indicator of body fatness. It is not a direct measurement of fat, but research has shown that BMI measurements correlate to direct measurement. It’s an inexpensive and easy-to-perform way to screen for possible weight issues that may lead to health problems. BMI is measured differently in adults than in children, so it is important to use the proper calculator to find out yours and your child’s separately.

BMI is not used to diagnose health issues, but it can be an early screening tool. Your health care provider may use additional information, such as family history, information about diet and exercise or a measurement of skinfold thickness or other tests to determine whether excess fat is a problem.

What does my child’s BMI mean? For children and teens, BMI is evaluated using age- and gender-specific charts that take into account the different growth patterns for gender. Weight and the amount of fat in the body differ for boys and girls and those levels change as they grow taller and older.

These charts help health care providers determine how a child’s particular BMI reading compares to the readings of other U.S. children his or her age. The group is divided into percentiles that reflect whether a child is at a healthy weight, underweight, overweight or obese.

Children over age 2, or teens whose BMI is:

Less than the 5th percentile are considered underweight.

Between the 5th percentile and less than the 85th percentile are at a healthy weight.

In the 85th percentile to less than the 95th percentile are considered overweight.